Would the HTR 7000 be workable for L/R in a room that has slanted ceilings or should I pursue other options for L/R?
I was considering using SuperCenter XL and HTR7000 for L/R (and possibly for Surround too... not gotten that far yet).

The room size is 18 ft (length) by 15 ft (width). I am including a picture to show the slant. Note the cubes on the wall are NuTone Sensonic - as prior owners had entire house intercom system and NuTone speakers in a couple of the rooms. You can ignore them. In 2020, we use texting as our whole house intercom

Thanks,
Doug

With the upslope of the ceiling, the HTR-7000 may not be optimal.

If you're looking for performance and if you don't mind rectangular speakers in that sloped ceiling, perhaps the MPXor SPS would work. Perhaps a good local GoldenEar dealer/integrator might be able to visit and offer suggestions, too.

Thanks. That was helpful. I think I will just go with the 3D Array XL with INVISA 650 (surrounds) and SuperSub X.
I listened to the 3D Array XL at audio advice paired with the SuperSub X here in Raleigh. I was a bit worried about mids as at first they seemed weak - but once we played with the crossover, it sounded very balanced.

Thanks,
Doug